KALAELOA  City officials yesterday held a blessing for a desalination plant designed to produce 5 million gallons of potable water a day from seawater within three years, a plan that's grown more attractive this month with voluntary restrictions on water prompted by O'ahu's water shortage.

Water department employee Stephen Ayat puts his mouth where his paycheck comes from  desalinated water from the pilot project where the 5 million-gallons-a-day Kalaeloa Desalination Facility is being built. At $3.20 per thousand gallons, it should be good.

Jeff Widener  The Honolulu Advertiser

Clifford Jamile, manager and chief engineer of the Honolulu Board of Water Supply, said the $40 million plant will be built on land donated by the Navy after the closing of the Barbers Point Naval Air Station in 'Ewa.

"This is only one of several water resource alternatives we are pursuing to meet the needs of current and future residents, and offers a hedge against prolonged drought such as we've been experiencing in recent years," Jamile said.

He acknowledged that the technology remains a lot more expensive than pumping fresh water out of the ground, but believes it's important to continue planning for an increasing population and a declining water supply. He said the desalted water will come with an operation and maintenance price tag of $3.20 per thousand gallons, compared to less than a dollar per thousand gallons for groundwater.

Jamile said the plant, designed by Oceanit engineering, is in its first phase and completion is expected within two to three years. A pilot project with a test well began operating in June. A second well is expected to be drilled late this year.

The plant uses a reverse osmosis process that pumps seawater at high pressure through a series of mem-branes to separate the water from the salt, he said. The plant will draw seawater from 1,600-foot-deep wells on land because the water quality is better than pumping it out of the open ocean, Jamile said.

U.S. Sen. Dan Inouye, D-Hawai'i, said he is seeking federal money to support further desalination efforts. "I want to congratulate the Board of Water Supply for its very courageous step forward," he said.

Desalination has long been discussed in Hawai'i. The state operated a pilot plant not far from the new 20-acre site but shut it down because the technology was too complicated and expensive, Jamile said.

This latest project will have improved technology and an increased awareness that 'Ewa's projected demand for water might exceed supply by 2025.

Jamile said the plant is being built in such a way that it can be expanded to produce 35 million gallons a day of potable water.

He said the board needs to look at desalination as a way to conserve natural resources. If the technology works on the dry 'Ewa Plain, Jamile said, the board may propose another plant in Windward O'ahu.

The Rev. William Kaina presided over the blessing of the facility, prompting some murmurs of appreciation when his prayers were interrupted by a brief light rain.